Background: Rheumatoid arthritis (RA) patients have an increased risk of cardiovascular disease (CVD), partly due to an increased prevalence of cardiovascular risk factors, but also due to chronic systemic inflammation inducing atherosclerotic changes of the arterial wall. The aim of this study was to determine whether anti-inflammatory therapy for the treatment of RA has favorable effects on arterial wall inflammation in RA patients. Methods: Arterial wall inflammation before and after 6 months of anti-inflammatory treatment was assessed in 49 early and established RA patients using 18F-fluorodeoxyglucose-positron emission tomography with computed tomography (18F-FDG-PET/CT). Arterial 18F-FDG uptake was quantified as maximum standardized uptake value (SUVmax) in the thoracic aorta, abdominal aorta, carotid, iliac and femoral arteries. Early RA patients (n = 26) were treated with conventional synthetic disease modifying anti-rheumatic drugs with or without corticosteroids, whereas established RA patients (n = 23) were treated with adalimumab. Results: In RA patients, overall SUVmax was over time reduced by 4% (difference −0.06, 95%CI −0.12 to −0.01, p = 0.02), with largest reductions in carotid (-8%, p = 0.001) and femoral arteries (−7%, p = 0.005). There was no difference in arterial wall inflammation change between early and established RA patients (SUVmax difference 0.003, 95%CI −0.11 to 0.12, p = 0.95). Change in arterial wall inflammation significantly correlated with change in serological inflammatory markers (erythrocyte sedimentation rate and C-reactive protein). Conclusion: Arterial wall inflammation in RA patients is reduced by anti-inflammatory treatment and this reduction correlates with reductions of serological inflammatory markers. These results suggest that anti-inflammatory treatment of RA has favorable effects on the risk of cardiovascular events in RA patients.